Question

Find the mass of pure hydrogen chloride gas dissolved per litre of its solution if the normality of the solution is $0.15$N. [At. Wt. : $H=1,Cl=35.5$]

• A. $5.475g$
• B. $5.824g$
• C. $4.356g$
• D. $7.333g$

Answer 1

The correct option is A $5.475g$

The solution is $0.15$ N.
Hydrogen chloride $\left(HCl\right)$ contains one replaceable H atom.
Molar mass of $HCl$ $=(1+35.5)=36.5u$

The expression for the equivalent weight of an acid is as given below.
Equivalent weight $=\frac{\text{Molecular mass}}{\text{Number of replaceable H}}$
$HCl$ contains one replacable hydrogen.
Substitute values in the above expression.
$=\frac{36.5}{1}=36.5u$
The expression for the normality of solution is as given below.
$=\frac{\text{Solute in grams per litre of solution}}{\text{Equivalent weight in grams}}$
Solute in grams per litre of solution = Normality Equivalent weight in grams
The mass of pure hydrogen chloride gas dissolved per litre of its solution $=(0.15\times 36.5)g=5.475g/l$.